They also claimed forward Rob Schremp off waivers from the New York Islanders.

In addition, the Thrashers signed defenseman Mark Stuart to a three-year contract extension. The Thrashers acquired Stuart and center Blake Wheeler from Boston on Feb. 18 for center Rich Peverley and defenseman Boris Valabik.

Atlanta also received a fifth-round pick in the 2011 draft in the trade with Florida.

Dvorak, who had seven goals and 21 points for the Panthers, can be an unrestricted free agent after the season. Bergfors is a pending restricted free agent.

Bergfors has 29 points, including 11 goals, for Atlanta. He has 74 points in 142 career games with Atlanta and New Jersey.

Rissmiller appeared in only one game with Atlanta this season.

Schremp has 22 points (10 goals, 12 assists) in 45 games with the Islanders.